So, this is event is a bit different in its construction. It's not "the main event of the patch" in that the Dockyard and finishing the Novorossiysk is. Also there are Clan Battles going on.
This was a side-event that was created to drive website engagement. As a fun, "but wait, there's more!" there's also a raffle associated with completing an Ornament mission, and a super prize the whoever wanted to try-hard the hardest and getting the biggest goal for an Ornament.
Regions were allowed to opt-in, and we did. Specifically we knew there could be concerns about players wanting to COMPLETE ALL THE THINGS! Some Ornaments were dialed back to more achieveable metric because of this.
While 1k BaseXP is doable in a Co-Op Battle, it's a rare event. This bar wasn't set for Xo-Op compatibility, however, but more of a polite challenge to achieve to get a small reward. While there are some PvE focused players, achieving 1k Base XP in a Random Battle is quite achievable on win, so it's a very doable alternative as there's no pressure to when or how quickly it can happen. The 1k Base XP in Naval Battles is frustrating in that attempts are limited, whereas this is not limited at all.